There are two parts to this program: a section on strengthening research infrastructure at Muhimbili University and a second section that addresses a research question of relevance to Tanzania. We propose to focus on development of capacity and research in the field of nutrition and HIV/AIDS. Our aims for infrastructure strengthening include: To develop a state-of-the-art research laboratory for nutritional analyses at Muhimbili University, including assessment of micronutrients and macronutrients; to validate a food frequency questionnaire and to develop data programs for assessment of dietary intake in Tanzanian populations; to strengthen the capacity of individual researchers in Tanzania to undertake research in the area of nutrition and HIV/AIDS; and to disseminate results from this research to members of academic and policy institutions. In the research part of the program, we propose to recruit 300 pregnant women who are infected with HIV and assign them to receive selenium or placebo. All women will be given standard prenatal care, including nevirapine for the prevention of mother-to-child transmission and prenatal multivitamin supplements. We will ascertain the effect of the selenium supplements on intermediate outcomes predictive of the risks of transmission of the virus and to disease progression. This is an exploratory study that we envision may lead to a larger scale research proposal that could lead to funding from NIH. The study is designed to take advantage of the infrastructure development and capacity strengthening that we have described above. The program will be carried out as a collaborative effort between Muhimbili University College of Health Sciences, Dar-es-Salaam, Tanzania and the Harvard School of Public Health, Boston, MA.